Smells bad (5)
I believe the answer is:
reeks
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">smells bad</span>' is the definition.<br/ ><span class="explanation-format__explanation">(reeking is a kind of smelling bad)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for reeks that I've seen before include "Smells bad" , "Gives off a strong unpleasant smell" , "Smells very strongly" , "Macgillycuddy's - -" , "Is humming" .)